<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1,user-scalable=no">
</head>
<body>
<div class="content_body">
    
</div>
<script>
    window.onload=function () {
        setTimeout(()=>{
            show();
        },5000)

    };
    let show = () => {
        var text = document.getElementsByClassName('content_body')[0];
        text.innerHTML = '你还！';
    }
    // 从一个数组中返回偶数
    let arr=[1,2,3,4,5,6,7,8]
    let arrnew=arr.filter(item=>item%2===0)
    console.log(arrnew)
</script>
</body>
</html>